Dynamic balancing of rotating objects is known in the prior art. Reference is made to the following patents: U.S. Pat. No. 3,164,413 to Salathiel, U.S. Pat. No. 3,316,021 to Salathiel, U.S. Pat. No. 3,346,303 to Wesley, U.S. Pat. No. 3,376,075 to Mitchell, U.S. Pat. No. 3,733,923 to Goodrich, U.S. Pat. No. 3,799,619 to LaBarber, U.S. Pat. No. 3,913,980 to Cobb, U.S. Pat. No. 3,953,074 to Cox, U.S. Pat. No. 4,388,841 to Gamble, U.S. Pat. No. 4,674,356 to Kilgore, U.S. Pat. No. 5,048,367 to Knowles, U.S. Pat. No. 5,142,936 to McGale, U.S. Pat. No. 5,253,928 to Patti, U.S. Pat. No. 5,503,464 to Collura and U.S. Pat. No. 6,128,952 to LeBlanc describe inventions used to dynamically balance rotating objects, usually vehicle wheels.
U.S. Pat. Nos. 3,164,413 and 3,316,021 to Salathiel describe a hollow annular hoop containing a plurality of spherical weights and a damping fluid. In use, the hoop is attached to a rotating wheel perpendicular to the axis of rotation and concentric to the axis of rotation. The apparatus of the Salathiel patents has the disadvantage of not providing a feasible means of attachment to a vehicular wheel. Furthermore, the Salathiel patents utilize a deformable material for the annular concentricity of the hoop during operation.
U.S. Pat. No. 3,346,303 to Wesley describes a hollow annular hoop containing a plurality of spherical weights and a measured amount of damping fluid. Wesley provides a hoop with an apex at the outer perimeter so as to reduce the area of contact between the spherical weights and the hoop. The hoop is constructed of a metal formed or welded into the proper shape or configuration. The hoop is attached to the wheel of a vehicle by means of attachment to a mounting fixture, which has several precut lug nut holes adapted to fit a wheel.
U.S. Pat. No. 3,376,075 to Mitchell describes a dynamic wheel balancer, which has a hollow annular hoop with a plurality of spherical weights and a damping fluid. The hoop is attached to a mounting fixture, which is adapted to fit a variety of wheel and lug nut configurations. The annular hoop is constructed by attaching a U-shaped channel onto a plate in a fluid tight manner.
U.S. Pat. No. 3,733,923 to Goodrich describes a balancer for rotating masses, which uses an annular hoop, spherical weights, and a damping fluid. The hoop contains a continuous metallic race containing carbon steel balls in a damping fluid. The hoop contains a small section on the interior portion, which is removable for adding the weights and fluid.
U.S. Pat. No. 3,799,619 to LaBarber describes a vibration dampening assembly, which comprises an annular hoop and spherical weights within the hoop. The outer perimeter of the hoop wall is made up of deformable material so as to assist in retaining the spherical weights in position after they have been distributed by the rotating of the hoop.
U.S. Pat. No. 3,913,980 to Cobb for a dynamic wheel balancing apparatus discloses an annular hoop with spherical weights, which is placed around a wheel inside a tire of a vehicle. The invention uses non-metallic weights and a damping fluid. The hoop is made of an elastic material, which can deform in use at high rotational speeds.
The publication Design News described the concept of xe2x80x9cSelf-Compensating Balancing in Rotating Mechanismsxe2x80x9d, in an article dated Apr. 28, 1965. Four requirements for successful application of the method for self-compensating balancing are described. First, there must be inertial forces on the rotating system that cause the mass center to misalign with the rotation center of the support bearings. Second, the rotating system must operate far away from its critical or resonant speed. Third, the bearing must have resiliency. Fourth, the rotor must be sufficiently balanced to avoid damage to itself as it passes through its critical speed during start-up.
The prior art does not provide a practical, and effective device or apparatus for realizing the benefits of dynamical balancing for many possible applications, including vehicular wheel balancing. The prior art fails to provide a design with the durability, ease of installation, and broad compatibility with a range of vehicle wheels that is provided by the instant invention. Additionally, the prior art fails to provide a design with a product cost commensurate with the economic benefits provided by dynamical wheel balancing.
The invention relates to a wheel balancing device having at least two hollow ballast chambers, each defining an interior cavity or compartment. The interior cavities of the respective ballast chambers do not communicate with one another. A movable mass or medium is contained within each of the interior cavities and is freely movable within the respective ballast chamber. An attachment device is provided to secure the ballast chambers to the wheel.